Optical scanning apparatus has become popular apparatus to be used in scanners, photocopiers, and FAX machines, with functions continually promoted, resulting in growing number of control key pads just like most of electronic products. The negative effect of the trend on product evolution can be seen as follows.
Obviously the growing number of the key pads means cost increase and size expansion. On the other hand the existence of key pads make hardware relatively complicate, leading to more complicate fabrication process as a result of higher difficulty in allocating mechanism and processing circuit connection, and hence the increase of cost and failure rate in producing the product can not be avoided.
It is also obvious that real key pads and associated circuits may bring about higher failure rate for users of the product.
Therefore it is worth while to develop virtual key pads for performing functions of real key pads (to replace real key pads), especially for optical scanning apparatus.